1. Field of the Invention
The present invention is related to an AC adaptor integral-type household-power-line coupler applied to a household-power-line communication apparatus, capable of simply constructing a local area network (LAN) in low cost.
2. Description of Related Art
Recently, strong needs for constructing local area networks (LANs) in simple manners and in low cost have been made in small-scalled offices and homes.
Conventionally, in order to constitute local area networks, methods for installing leased communication lines have been conducted. On the other hand, there is another trend that wireless communication and household power lines (electric light lines) are employed without using the leased communication lines in order to establish local area networks. Then, this trend is gradually increased. In household-power-line communications, household-power-line converting/supplying units (AC adaptors etc.) for supplying electric power to communication appliances capable of performing communications, and also, household-power-line carrier signal coupling units (household-power-line couplers) for transmitting/receiving communication signals to/from household power lines must be prepared respectively.
A conventional household-power-line communication appliance will now be explained. FIG. 1 is a structural diagram of this conventional household-power-line communication appliance. In this drawing, a communication terminal 1 is connected to an AC adaptor 2, a household-power-line modem 5, and a household-power-line coupler 3. The AC adaptor 2 supplies electric power to the communication terminal 1. The household-power-line modem 5 modulates and/or demodulates a communication signal. The household-power-line coupler 3 transmits/receives a communication signal to/from the household power line. In the case that a household-power-line communication is carried out, the AC adaptor 2, the household-power-line modem 5, and the household-power-line coupler 3 are connected to the communication terminal 1 so as to be used.
However, the above-explained conventional method and LAN constructing method owe the following problems:
(1) To perform a household-power-line communication by the communication terminal 1, the AC adaptor 2, the household-power-line modem 5, and the household-power-line coupler 3 must be separately connected to the communication terminal 1. Accordingly, the cumbersome connecting operations are necessarily required. Thus, there is such a problem that handling characteristics and operability are deteriorated in the case that the communication terminal 1 is moved.
(2) At least two sets of household-power-line plug units are required which are occupied by these units, so that wiring lines are made complicated. Therefore, there are problems that outer appearances are deteriorated and designing senses are also deteriorated.